Interesting note. In siege of the warmind (DB mission where you fight Omnigul inside the warmind), there is an open door to the new DLC area, but a door is closed at the end preventing you from getting to the full area. If a player stands here, he can get to Omnigul in the room during the event(which triggers the door to reopen) and you can kill Omnigul. Killing her doesn't make the door open, even on heroic, and it seems to stop the mission from progressing. After killing her, 2 super strong acolytes spawn. Killed them too, but still the door doesn't open.